WO2023089826A1

WO2023089826A1 - Resin composition, resinous coating material, insulated electrical wire, automotive wire harness, and method for producing insulated electrical wire for use in automotive wire harness

Info

Publication number: WO2023089826A1
Application number: PCT/JP2021/042790
Authority: WO
Inventors: 賢司高橋; 秀幸大菅
Original assignee: 古河電気工業株式会社; 古河As株式会社
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2023-05-25
Also published as: CN116490554A; US20230272198A1

Abstract

A resin composition including the following components (A) and (B) and containing the following component (C) and/or the following component (D): (A) a low-density polyethylene resin, (B) an ethylene/vinyl acetate copolymer resin, (C) a thioether compound, and (D) a fluororubber. The content of the component (A) and the content of the component (B) are 5-40 parts by mass and 60-95 parts by mass, respectively, per 100 parts by mass of the sum of the components (A) and (B). The total content of the components (C) and (D) is 0.05-1 part by mass per 100 parts by mass of the sum of the components (A) and (B). In the component (B), the proportion of vinyl acetate units is 40 mass% or less.

Description

Resin composition, resin coating material, insulated wire, automotive wire harness, and method for producing insulated wire used for automotive wire harness

The present invention relates to a resin composition, a resin coating material, an insulated wire, a wire harness for automobiles, and a method for producing an insulated wire used for wire harnesses for automobiles.

Flame-retardant insulated wires are widely used in various white goods, OA equipment, and the like. Insulated wires used in automobiles and the like are also required to have various properties such as flame resistance, heat resistance, flexibility, and mechanical properties. So far, many reports have been made on resin compositions that realize insulated wires with flame retardance, heat resistance, flexibility, and mechanical properties by using them as coating materials for conductors. there is
Resins such as polyethylene and ethylene-vinyl acetate copolymers are widely used as resin compositions for insulated wires having such desired properties.

For example, in Patent Document 1, a conductor is coated with a resin composition containing an ethylene-vinyl acetate copolymer having a vinyl acetate content within a specific range, a brominated flame retardant, an epoxy compound, and antimony trioxide. It is described that a flame-retardant electric wire having excellent flame retardancy, water resistance and oil resistance can be obtained by cross-linking the material.

Patent Document 2 describes a resin composition that can be used as a coating material for a conductor to obtain an insulated wire having an insulating layer that has excellent flexibility, oil resistance, and mechanical strength. there is This resin composition has a density within a specific range, and is a copolymer of unsaturated hydrocarbon having 4 or more carbon atoms and ethylene, a copolymer of acrylic acid ester and ethylene or a methacrylic acid ester and ethylene copolymer. and specific amounts of a flame retardant and a cross-linking aid.

In Patent Document 3, it has excellent flame retardancy, heat resistance, cold resistance (low temperature properties), and oil resistance, and is also excellent in mechanical strength such as tensile mechanical properties and wear resistance. A non-halogen flame-retardant resin composition used for forming an insulating film for an insulated wire is disclosed. This resin composition contains 100 parts by mass or more and 250 parts by mass or less of a metal hydroxide and 1% by mass or more and 20% by mass of a silicone oil having a viscosity of 3000 mPa s or less at 25° C. based on 100 parts by mass of a polyolefin resin. The polyolefin resin contains 30% by mass or more and 85% by mass or less of polyethylene having a melting point (Tm) by the DSC method of 120° C. or more and 130° C. or less and a density of 0.925 or more and 0.945 or less, and ethylene-acetic acid. It contains 10 to 60% by mass of a vinyl copolymer (EVA) and 5 to 30% by mass of a maleic anhydride-modified ethylene α-olefin copolymer having a DSC melting point of 60° C. or less.

Patent Document 4 describes an insulated wire and cable that uses a halogen-free flame-retardant resin composition that has flame resistance, oil resistance, fuel resistance, and trauma resistance. This halogen-free flame-retardant resin composition contains, as a base polymer, 60 to 70% by mass of linear low-density polyethylene, 10% by mass or more of an ethylene-vinyl acetate copolymer having a melt flow rate (MFR) of 100 or more, and a maleic acid-modified polyolefin of 10 to 20% by mass, and a metal hydroxide added at a rate of 150 to 220 parts by mass with respect to 100 parts by mass of the base polymer, and carbon black. The metal hydroxide and the carbon black are added at a mutual addition ratio (metal hydroxide:carbon black) of 15:1 to 100:1, and are crosslinked.

Patent Document 5 describes an in-vehicle electric wire/cable that has high heat resistance and flexibility, as well as excellent mechanical strength, abrasion resistance, and flame retardancy. This in-vehicle electric wire/cable is coated with a resin composition obtained by adding a combination of two specific antioxidants and a specific brominated flame retardant to an ethylene-based copolymer containing ethylene-ethyl acrylate copolymer. We have it as a material.

JP 2017-111920 A International Publication No. 2018/074233 International Publication No. 2016/175076 JP 2015-038869 A JP 2015-164114 A

When a combination of polyethylene and ethylene-vinyl acetate copolymer is used as the base resin constituting the coating material for electric wires, the ethylene-vinyl acetate copolymer has a vinyl acetate (polar molecule) component introduced into the polymer structure. Therefore, by increasing the proportion of the ethylene-vinyl acetate copolymer in the base resin, the adhesion to the metal is enhanced. Therefore, the adhesion to the conductor is improved, and the degree of freedom in handling and processing of the insulated wire can be increased.
However, the improvement of the adhesion to the metal increases the contact wear with the metal die during extrusion processing, and the friction between the inside of the die and the coating material increases. As a result, drool (rubbing residue) is likely to occur at the tip of the die. Accumulation of die scum may impair the appearance (surface roughness) and manufacturability (yield due to bumps, protrusions, etc.) of manufactured products.
In addition, if the adhesive strength between the resin coating material and the conductor is high, the conductor wires may be drawn out irregularly or may be broken in the wire stripping process, resulting in poor wire stripping performance. Conversely, if the adhesion between the resin coating material and the conductor is low, a shrinkback phenomenon occurs due to the shrinkage of the insulator after wire stripping, and the conductor is exposed at the end, and moisture enters the exposed part. This can easily lead to electrical problems.

On the other hand, by increasing the proportion of polyethylene in the base resin, the wear resistance of the wire can be improved. On the other hand, polyethylene has a high degree of crystallinity, and this degree of crystallinity increases as the density increases. Therefore, when the proportion of polyethylene in the base resin is increased or high-density polyethylene is used, other low-molecular-weight components tend to migrate (bleed, bloom) to the surface layer. Therefore, the risk of contamination of the production line increases.

In view of the above situation, the present invention provides an insulated wire having an excellent appearance by being used to form an insulating film (resin coating material layer) on an insulated wire, thereby improving the film-forming property around the conductor. It is an object of the present invention to provide a resin composition capable of achieving desired excellent flame retardancy and mechanical properties suitable for insulated wires. In addition, the present invention provides a resin coating material using the above resin composition, an insulated wire having an insulating film containing the resin coating material, an automotive wire harness having the insulated wire, and an insulated wire used for the automotive wire harness. An object of the present invention is to provide a method for producing the

As a result of investigations aimed at solving the above problems, the present inventors have found a resin composition for an insulating coating material (resin coating material) using a combination of a low-density polyethylene resin and an ethylene-vinyl acetate copolymer as a base resin. , by blending a specific amount of at least one of a thioether compound and a fluororubber, foreign substances such as resin scum (so-called "thickness") are generated at the extrusion port of the extrusion die during the formation of an insulating film by extrusion coating. In addition, bleeding is suppressed in the subsequent processes, preventing contamination of the production line (guide pulleys, etc.), and the resulting resin coating material has excellent flame resistance and mechanical strength. . The present invention has been completed through further studies based on these findings.

That is, the above problems have been solved by the following means.
<1>
Containing the following components (A) and (B), and containing at least one of the following components (C) and (D),
(A) low density polyethylene resin,
(B) ethylene-vinyl acetate copolymer resin,
(C) a thioether compound,
(D) fluororubber,
The total content of components (A) and (B) is 100 parts by mass, the content of component (A) is 5 to 40 parts by mass, the content of component (B) is 60 to 95 parts by mass, and component (A ) and the total content of components (C) and (D) is 0.05 to 1 part by mass per 100 parts by mass of the total content of (B),
A resin composition in which the proportion of the vinyl acetate component in component (B) is 40% by mass or less.
<2>
The resin composition according to <1> above, wherein the proportion of the vinyl acetate component in the component (B) is 7% by mass or more.
<3>
The content of the component (C) is 0.7 parts by mass or less and the content of the component (D) is 1 part by mass or less per 100 parts by mass of the total content of the components (A) and (B). , the resin composition according to <1> or <2>.
<4>
In the total content of 100 parts by mass of components (A) and (B), the content of component (A) is more than 20 parts by mass and 40 parts by mass or less, and the content of component (B) is 60 parts by mass or more and 80 parts by mass. <1> to <3>, wherein the content of component (C) is 0.5 parts by mass or less relative to the total content of 100 parts by mass of components (A) and (B). The resin composition according to any one of the above.
<5>
In the total content of 100 parts by mass of the components (A) and (B), the content of the component (A) is 5 parts by mass or more and 20 parts by mass or less, and the content of the component (B) is 80 parts by mass or more and 95 parts by mass. parts by mass or less, and the total content of the components (C) and (D) with respect to the total content of 100 parts by mass of the components (A) and (B) is 0.5 to 1 part by mass, the <1 > to the resin composition according to any one of <3>.
<6>
The VA value calculated by the following formula is 15 or more, and the total content of the components (C) and (D) with respect to the total content of 100 parts by mass of the components (A) and (B) is 0.5 to 1. The resin composition according to any one of <1> to <5>, which is parts by mass.

VA value = [content (parts by mass) of component (B) in 100 parts by mass of total content of components (A) and (B)] x [proportion of vinyl acetate component in component (B) (% by mass) ]/100

<7>
<1> to <6>, wherein the resin composition contains at least one of a flame retardant, an antioxidant, a processing aid, and a cross-linking aid in addition to the components (A) to (D). The resin composition according to any one of the above.
<8>
The resin composition according to any one of <1> to <7>, which is used for automotive wire harnesses.
<9>
A resin coating material obtained by cross-linking the resin composition according to any one of <1> to <8>.
<10>
An insulated wire, wherein the insulating film has the resin coating material according to <9>.
<11>
A wire harness for an automobile, comprising the insulated wire according to <10>.
<12>
The resin composition according to any one of <1> to <8> is extrusion-coated on the conductor to provide a layer of the resin composition, and the layer of the resin composition is irradiated with an electron beam of 80 to 250 kGy. A method for manufacturing an insulated wire used in a wiring harness for an automobile, comprising steps.

In the present invention, a numerical range represented using "~" means a range that includes the numerical values described before and after it as lower and upper limits.

By using the resin composition of the present invention for forming an insulating film (resin coating material layer) of an insulated wire, it is possible to improve the film-forming property around the conductor, and the obtained insulated wire has an excellent appearance. It is possible to realize desired excellent properties suitable for insulated wires in terms of flame retardancy and mechanical properties. By using the resin coating material of the present invention as a constituent material of the insulating film of the insulated wire, it contributes to the improvement of the productivity of the insulated wire, and has excellent appearance, flame retardancy and mechanical properties. It is possible to obtain an insulated wire exhibiting properties. In the wire harness for automobiles of the present invention, the insulated wires constituting the wire harness for automobiles have the resin coating material on the insulating film, and are excellent in productivity, appearance, flame retardancy and mechanical properties. Excellent. According to the method of manufacturing an insulated wire used for a wiring harness for an automobile according to the present invention, it is possible to obtain an insulated wire having the above-described excellent characteristics or superiority while suppressing contamination of the production line (guide pulleys, etc.).

[Resin composition]
The resin composition of the present invention comprises (A) a low-density polyethylene resin (also referred to as component (A)), (B) an ethylene-vinyl acetate copolymer resin (also referred to as component (B)), and a thioether compound. (C) (also referred to as component (C)) and at least one of fluororubber (D) (also referred to as component (D)).
Components (A) to (D) and optional components described below may be used singly or in combination of two or more.
Components contained in the resin composition of the present invention are described below.

<(A) Low density polyethylene resin>
The resin composition of the present invention contains (A) a low-density polyethylene resin as a resin component constituting the base resin. In the present invention, "low density polyethylene resin" means polyethylene resin having a density of 0.929 g/cm ³ or less. Examples include "low density polyethylene (LDPE)" and "very low density polyethylene (VLDPE)".
The low density polyethylene resin used in the present invention preferably has a density range of 0.870-0.929 g/cm ³ , more preferably a density range of 0.910-0.929 cm ³ . The density of polyethylene can be determined according to JIS K 7112.

The content of component (A) contained in the resin composition of the present invention is 5 to 40 parts by mass per 100 parts by mass of the total content of components (A) and (B). From the viewpoint of adjusting the adhesion between the resin coating material and the conductor to an appropriate level, the content of component (A) in the total content of 100 parts by mass of components (A) and (B) is 10 to 35 parts by mass. preferably 15 to 30 parts by mass.
Further, by increasing the proportion of (B) the ethylene-vinyl acetate copolymer contained in the resin composition, the flexibility and flame retardancy of the coating material can be improved. Especially in the field of automotive applications, there is a demand for further improvement in the flexibility of coating materials from the viewpoints of large currents in hybrid vehicles and electric vehicles that have been developed in recent years, ease of wiring, and space saving. Therefore, from the viewpoint of imparting flexibility to an insulated wire in which the conductor is coated with the resin composition, the total content of components (A) and (B) is 100 parts by mass. The content is preferably 20 parts by mass, more preferably 5 to 10 parts by mass. Further, from the viewpoint of imparting abrasion resistance to an insulated wire obtained by coating the conductor with the resin composition, the content of the component (A) is preferably 20 to 40 parts by mass, and 30 parts by mass. It is more preferable to make it to 40 parts by mass.

Further, the melt flow rate (MFR) of the component (A) used in the present invention is preferably 0.1 to 20 g/10 minutes (load 2.16 kg, temperature 190 ° C.), and 0.2 to 10 g/ 10 minutes is more preferred.
By setting the melt flow rate of component (A) within the above preferred range, the load on kneading equipment and extruders can be further reduced during the preparation of the resin composition and the production of insulated wires or wire harnesses. The dispersibility of each component in the composition can also be enhanced.
Melt flow rate (MFR) can be measured by a method based on JIS K7210 using an extrusion type plastometer (melt indexer) defined by JIS K6760 as a test machine.

In addition, the component (A) used in the present invention may be, for example, high-pressure radical method (high-pressure method) low-density polyethylene or metallocene-catalyzed linear low-density polyethylene. For the polyethylene, for example, the description of Japanese Patent Application No. 2016-072380 can be referred to. Component (A) used in the present invention may be a modified form of polyethylene (for example, an acid-modified form).

The polyethylene used in the present invention can be synthesized by conventional methods, and commercially available products can be used. Specific examples of commercially available products include Petrothene 180R, Petrothene 170R, and Petrothene 173R manufactured by Tosoh Corporation, Sumikasen F218-0, Sumikasen F200, and Sumikasen G401 manufactured by Sumitomo Chemical Co., Ltd., Novatec LF443 manufactured by Japan Polyethylene Corporation, Novatec LF280H, Novatec LF448K1, NUC-9060 and ENGAGE-8100 manufactured by NUC, and NUCG-5130 manufactured by Dow Elastomer (all trade names).

<(B) Ethylene-Vinyl Acetate Copolymer Resin>
The resin composition of the present invention contains component (A) and (B) an ethylene-vinyl acetate copolymer resin as resin components constituting a base resin. In the resin composition of the present invention, the content of component (B) is 60 to 95 parts by mass based on the total content of components (A) and (B) of 100 parts by mass. From the viewpoint of improving the adhesion between the resin coating material and the conductor, the content of the component (B) is preferably 65 to 90 parts by mass, more preferably 70 to 85 parts by mass.
In particular, from the viewpoint of imparting flexibility to an insulated wire in which the resin composition is coated around a conductor, the content of component (B) in 100 parts by mass of the total content of components (A) and (B) is preferably 80 to 95 parts by mass, more preferably 90 to 95 parts by mass. In addition, from the viewpoint of imparting abrasion resistance to an insulated wire obtained by coating the conductor with the resin composition, the content of the component (B) is preferably 60 to 80 parts by mass. It is more preferable to make it to 70 parts by mass.
The form of polymerization of the ethylene-vinyl acetate copolymer used in the present invention may be block, random or graft.

In the component (B), the content ratio of the vinyl acetate component constituting the component (B) is 40% by mass or less. From the viewpoint of adjusting the adhesion between the resin coating material and the conductor to an appropriate level, the content of the vinyl acetate component is preferably 30% by mass or less, more preferably 20% by mass or less. From the same viewpoint as above, the content of the vinyl acetate component is preferably 7% by mass or more, more preferably 9% by mass or more. By setting the content ratio of the vinyl acetate component within the above range, the resin coating material produced using the resin composition of the present invention can acquire sufficient mechanical properties such as tensile strength and tensile elongation, and furthermore, the insulated wire can be improved. Flame retardancy can be further improved.

In addition, from the viewpoint of imparting a desired adhesion between the resin coating material and the conductor, the VA value calculated by the following formula is preferably 7 to 30, more preferably 8 to 28, and even more preferably is 10-25, preferably 10-20.

VA value = [content (parts by mass) of component (B) in 100 parts by mass of total content of components (A) and (B)] x [proportion of vinyl acetate component in component (B) (% by mass) ]/100

The melt flow rate (MFR) of component (B) used in the present invention is preferably 0.1 to 10 g/10 minutes (load 2.16 kg, temperature 190° C.), more preferably 0.5 to 5 g/10 minutes.
By setting the melt flow rate of the component (B) within the above preferred range, the load on kneading equipment and extruders can be further reduced during the preparation of the resin composition and the production of insulated wires or wire harnesses. The dispersibility of each component in the composition can also be enhanced.
Melt flow rate (MFR) can be determined in the same manner as described above.

The ethylene-vinyl acetate copolymer (B) used in the present invention can be synthesized by a conventional method, and commercially available products may be used. Specific examples of commercially available products include Evaflex V5961, Evaflex V5274, and Evaflex EV170 (all trade names) manufactured by Mitsui DuPont Polychemicals.

The total content of the components (A) and (B) in the resin composition of the present invention is from the viewpoint of improving the adhesion between the resin coating material and the conductor, and imparting flexibility and abrasion resistance. , preferably 7 to 80% by mass, more preferably 10 to 75% by mass, even more preferably 20 to 70% by mass. Further, the total content of the components (A) and (B) in the resin composition is preferably 30 to 80% by mass, preferably 40 to 75 parts by mass, and 50 to 75 parts by mass. It is also preferable to set

<(C) Thioether compound, and (D) fluororubber>
The resin composition of the present invention contains a specific amount of at least one of (C) a thioether compound and (D) a fluororubber. As a result, when the resin composition is coated around the conductor, the adhesion between the conductor and the resin coating material can be controlled, and the film formability at the time of coating (during wire production) and the processing of the wire after coating can be improved. can enhance sexuality.
In the resin composition of the present invention, the total content of components (C) and (D) is 0.05 to 1 part by mass per 100 parts by mass of the total content of components (A) and (B). From the viewpoint of adjusting the adhesion between the resin coating material and the conductor to an appropriate level, the total content of the components (C) and (D) is preferably 0.1 to 1.0 parts by mass. .1 to 0.8 parts by mass, or 0.1 to 0.5 parts by mass.
In the present invention, the "total content of components (C) and (D)" is contained in the resin composition when the resin composition contains only one of components (C) and (D) It means the content of one component, and when both components (C) and (D) are included, it means the total content of components (C) and (D). The resin composition of the present invention preferably contains only one of components (C) and (D).
When the resin composition of the present invention contains the component (C) and does not contain the component (D), the total content of the components (A) and (B) is 100 parts by mass. The content becomes 0.05 to 1 part by mass. In this case, the content of component (C) is preferably 0.1 to 1 part by mass per 100 parts by mass of the total content of components (A) and (B).
Further, when the resin composition of the present invention contains the component (D) and does not contain the component (C), the component (D ) is 0.05 to 1 part by mass. In this case, the content of component (D) is preferably 0.1 to 1 part by mass per 100 parts by mass of the total content of components (A) and (B).

((C) thioether compound)
Component (C) that can be used in the present invention is not particularly limited as long as it is a compound having a thioether bond, but the melting point thereof is preferably 60° C. or lower. Examples of such a thioether compound include thioether-based antioxidants (antioxidants having a thioether bond) used as antioxidants for electric wire coating materials. For example, dilauryl 3,3'-thiodipropionate (melting point: 40-42°C), dimyristyl 3,3'-thiodipropionate (melting point: 48-53°C), distearyl 3,3'-thiodipropionate 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diyl bis[3-dodecylthiopropionate] (melting point: 65-67° C.) 46-52°C, also known as bis[3-(dodecylthio)propionic acid]2,2-bis[[3-(dodecylthio)-1-oxopropyloxy]methyl]-1,3-propanediyl) . Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diyl bis[3-dodecylthio propionate] is preferred.
A commercially available thioether-based antioxidant may be used in the resin composition of the present invention. Commercially available products include, for example, ADEKA STAB AO-412S (trade name, manufactured by ADEKA).

((D) fluororubber)
Component (D) that can be used in the present invention includes homopolymer or copolymer rubbers containing fluorine atoms in the main chain or side chains. A fluororubber is usually obtained by (co)polymerizing monomers containing fluorine atoms.
Examples of such component (D) include, but are not particularly limited to, perfluorohydrocarbons such as tetrafluoroethylene and hexafluoropropylene, and fluorine-containing monomers such as partially fluorinated hydrocarbons (for example, vinylidene fluoride). Further, copolymer rubbers of these perfluorohydrocarbons and/or fluorine-containing monomers and hydrocarbons such as ethylene and/or propylene may be mentioned.
Specifically, tetrafluoroethylene-propylene copolymer rubber (FEPM), tetrafluoroethylene-fluorinated (eg, hexafluoro)propylene copolymer rubber, tetrafluoroethylene-perfluorovinyl ether copolymer rubber (FFKM), vinylidene fluoride rubber (FKM, eg, vinylidene fluoride-hexafluoropropylene copolymer rubber), and the like.
Furthermore, copolymer rubbers of the aforementioned perfluorohydrocarbon and/or fluorine-containing monomers and chloroprene and/or chlorosulfonated polyethylene are also included.
Among these fluororubbers, tetrafluoroethylene-propylene copolymer rubber and vinylidene fluoride-hexafluoropropylene copolymer rubber are preferred, and tetrafluoroethylene-propylene copolymer rubber is more preferred.
A commercially available fluororubber may be used for the resin composition of the present invention. Examples of commercially available products include Viton FreeFlow 10 (trade name, manufactured by Chemours).

In particular, the content of component (A) is 5 parts by mass or more and 20 parts by mass or less in 100 parts by mass of the total content of components (A) and (B) in the resin composition, and the content of component (B) is 80 parts by mass or more and 95 parts by mass or less, from the viewpoint of suppressing the adhesion between the resin coating material made of the resin composition and the conductor, components (C) and (D) contained in the resin composition The total content is preferably 0.5 to 1 part by mass, preferably 0.7 to 1 part by mass, per 100 parts by mass of the total content of components (A) and (B). In this case, the resin composition preferably contains only one of components (C) and (D).
Further, the content of component (A) is more than 20 parts by mass and 40 parts by mass or less in the total content of 100 parts by mass of components (A) and (B) in the resin composition, and the content of component (B) is 60 parts by mass or more and less than 80 parts by mass, the viewpoint of suppressing the adhesion between the resin coating material and the conductor made of the resin composition, and bleeding and blooming (hereinafter, these are collectively referred to simply as "bleeding" ) from the viewpoint of suppressing the is more preferably 0.6 parts by mass or less, and preferably 0.5 parts by mass or less. In this case, it is also preferable that the resin composition does not contain component (C) and contains 0.3 parts by mass or more of component (D).
Further, in the same manner as described above, the content of component (A) is more than 20 parts by mass and 40 parts by mass or less in the total content of 100 parts by mass of components (A) and (B) in the resin composition, and component ( When the content of B) is 60 parts by mass or more and less than 80 parts by mass, the content of component (C) is preferably 0.7 parts by mass or less, more preferably 0.5 parts by mass or less, and 0.5 parts by mass or less. It is more preferably 3 parts by mass or less. In this case, it is also preferable that the component (D) is not included and the component (C) is included in an amount of 0.1 parts by mass or more.

Further, when the VA value is 15 or more, from the viewpoint of suppressing the adhesion between the resin coating material made of the resin composition and the conductor, the total amount of the components (C) and (D) contained in the resin composition The content is preferably 0.5 to 1 part by mass, more preferably 0.7 to 1 part by mass, per 100 parts by mass of the total content of components (A) and (B). In this case, the VA value is preferably 30 or less, more preferably 28 or less.

<Other ingredients>
In addition to the above components, the resin composition of the present invention may contain other components such as the following flame retardants, antioxidants, processing aids, and cross-linking aids within a range that does not impair the effects of the present invention. good.

<Flame retardant>
The present invention can contain a flame retardant within a range that does not impair the effects of the present invention. Examples of such flame retardants include brominated flame retardants and antimony flame retardants. The present invention preferably contains at least either a brominated flame retardant or an antimony flame retardant, and more preferably contains both a brominated flame retardant and an antimony flame retardant. The mixing ratio of the brominated flame retardant and the antimony flame retardant is such that the molar ratio of the bromine element to the antimony element is 2 to 5 times the molar ratio of the antimony element contained in the resin composition. It is preferably within the range of the amount of That is, it is preferable to contain the brominated flame retardant in an amount of 2 to 5 times the molar amount of bromine contained in the antimony flame retardant.
When the resin composition of the present invention contains a flame retardant, it preferably contains 33 to 45 parts by mass of the flame retardant in total with respect to 100 parts by mass of the total content of components (A) and (B).

(Brominated flame retardant)
The brominated flame retardant used in the present invention is preferably a bromine-containing compound. That is, the resin composition of the present invention preferably contains a bromine-containing compound as a flame retardant. Brominated flame retardants include, for example, brominated N,N'-ethylenebisphthalimide or compounds derived therefrom (collectively referred to as "brominated N,N'-ethylenebisphthalimide compounds"), N,N '-bis (bromophenyl) terephthalamide or compounds derived therefrom (collectively referred to as "N,N'-bis (bromophenyl) terephthalamide compounds"), brominated bisphenols or compounds derived therefrom (these (collectively referred to as “brominated bisphenol compounds”), 1,2-bis(bromophenyl)alkanes, and other organic bromine-containing flame retardants can be used. Among them, it is preferable to use, for example, brominated N,N'-ethylenebisphthalimide and/or 1,2-bis(bromophenyl)ethane.
By using brominated N,N'-ethylenebisphthalimide and/or 1,2-bis(bromophenyl)alkyl, preferably 1,2-bis(pentabromophenyl)ethane, as flame retardants, bleeding is minimized. It is possible to form a resin coating that does not occur.
A commercially available brominated flame retardant may be used as the brominated flame retardant used in the resin composition of the present invention. Examples of commercially available products include Cytex 8010 (trade name, manufactured by Albemarle).

When the resin composition of the present invention contains a brominated flame retardant, it preferably contains 15 to 35 parts by mass of the brominated flame retardant with respect to 100 parts by mass of the total content of components (A) and (B).

(Antimony flame retardant)
Examples of antimony-based flame retardants include antimony trioxide, antimony tetroxide, antimony pentoxide, and sodium antimonate. It is believed that antimony reacts with chlorine (halogen), and the generated gas blocks oxygen, thereby promoting the formation of a carbonized layer and trapping free radicals (thermal decomposition chain reaction stopping action). Among them, antimony trioxide is preferably contained in the present invention from the viewpoint of forming a more stable carbonized layer.
Commercially available antimony trioxide may be used in the present invention. Examples of commercially available products include PATOX-C (trade name, manufactured by Nippon Seiko Co., Ltd.).

When the resin composition of the present invention contains an antimony-based flame retardant, it preferably contains 5 to 15 parts by mass of the antimony-based flame retardant with respect to 100 parts by mass of the total content of components (A) and (B).

(Other flame retardants)
The resin composition of the present invention may contain, in addition to the brominated flame retardant and the antimony flame retardant, a flame retardant that can be normally used for insulating coatings of insulated wires. Examples of such flame retardants include metal hydroxides (hydroxide flame retardants) such as magnesium hydroxide and aluminum hydroxide. When the resin composition of the present invention contains a hydroxide-based flame retardant, it is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, relative to 100 parts by mass of the total content of components (A) and (B). preferable.

<Antioxidant>
The resin composition of the present invention may contain an antioxidant. Examples of such antioxidants include phenol compounds (phenol-based antioxidants) and imidazole compounds (imidazole-based antioxidants).
When the resin composition of the present invention contains an antioxidant, it preferably contains 2 to 6 parts by mass of the antioxidant with respect to 100 parts by mass of the total content of components (A) and (B).

(Phenolic antioxidant)
Phenolic antioxidants that can be used in the resin composition of the present invention include, for example, triethylene glycol-bis(3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate), 1,6- Hexanediol-bis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), pentaerythrityl-tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate), octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5,-di-t- Butyl-4-hydroxybenzyl)benzene, Tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, Isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate Among these, from the viewpoint of imparting high heat resistance to automobile wire harnesses, 3,5-di-t-butyl-4-hydroxyphenyl group or 3,5-di-t-butyl-4- Those having two or more hydroxybenzyl groups are preferred, and tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate and pentaerythrityl-tetrakis(3-(3,5-di-t-butyl -4-hydroxyphenyl)propionate) is particularly preferred.
A commercially available phenolic antioxidant may be used in the present invention. Commercially available products include, for example, Irganox 1010 (trade name, manufactured by BASF).

When the resin composition of the present invention contains a phenolic antioxidant, it contains 0.5 to 2 parts by mass of the phenolic antioxidant with respect to 100 parts by mass of the total content of components (A) and (B). is preferred.

(Imidazole antioxidant)
Examples of imidazole-based antioxidants that can be used in the resin composition of the present invention include 2-sulfanylbenzimidazole, 2-sulfanylmethylbenzimidazole, 4-sulfanylmethylbenzimidazole, 5-sulfanylmethylbenzimidazole and zinc salts thereof. 2-sulfanylbenzimidazole and its zinc salt are preferred.
In the present invention, a commercially available imidazole antioxidant may be used. Examples of commercially available products include Nocrac MBZ (trade name, manufactured by Ouchi Shinko Kagaku Co., Ltd.).

When the resin composition of the present invention contains an imidazole-based antioxidant, it is preferable to contain 1 to 4 parts by mass of the imidazole-based antioxidant with respect to 100 parts by mass of the total content of components (A) and (B). .

<Processing aid>
The resin composition of the present invention preferably also contains a processing aid. Preferred examples of processing aids include metallic soaps (lubricants).
Examples of metal soaps (lubricants) that can be used in the resin composition of the present invention include calcium stearate, zinc stearate and magnesium stearate.
Commercially available metal soaps may be used in the present invention. Commercially available products include, for example, Shinakared ZS-101 (trade name, manufactured by Shinagawa Kako Co., Ltd.).

When the resin composition of the present invention contains a metal soap, it preferably contains 0.5 to 2 parts by mass with respect to 100 parts by mass of the total content of components (A) and (B).

<Crosslinking aid>
The resin composition of the present invention preferably also contains a cross-linking aid. Examples of cross-linking aids include polyfunctional compounds, and compounds having two or more (preferably three or more, more preferably three to six) ethylenically unsaturated bonds (carbon-carbon double bonds) in the molecule. preferable.
Specific examples of cross-linking aids include (meth)acrylate compounds such as polypropylene glycol diacrylate and trimethylolpropane triacrylate, allyl compounds such as triallyl cyanurate, maleimide compounds, and divinyl compounds.
A commercially available cross-linking aid may be used in the present invention. Commercially available products include, for example, Ogmont T200 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).
The resin composition of the present invention preferably contains 1 to 4 parts by mass of a cross-linking aid per 100 parts by mass of the total content of components (A) and (B).

<Additive>
Various additives such as copper damage inhibitors, ultraviolet absorbers, dispersants, plasticizers, fillers, pigments, etc. may be added to the resin composition of the present invention, as long as they do not impair the effects of the present invention. It can be blended as appropriate. Examples of such additives include zinc compounds. Specific examples of zinc compounds include zinc sulfide and zinc oxide.

[Method for producing resin composition]
The resin composition of the present invention is prepared by blending the above-described components (A) to (D) and, if necessary, the above-described optional components, and using a batch type kneader such as a roll, kneader, or Banbury mixer or a twin-screw extruder. It can be obtained by melt-kneading with a commonly used kneading device such as.

[Insulated wire]
The insulated wire of the present invention has a layer made of a resin coating material obtained by cross-linking the resin composition of the present invention on the surface of a conductor (including conductor bundles and fiber core wires). The insulated wire of the present invention may have an intermediate layer or a shielding layer between the conductor and the layer made of the resin coating material.

When the cross-sectional area of the insulated wire of the present invention is 2 sq (square, JIS standard) or less, from the viewpoint of imparting abrasion resistance to the insulated wire, the resin composition of the present invention, which is a film-forming material, contains the component (A ) is preferably blended in a large amount. Specifically, the content of component (A) is preferably 20 to 40 parts by mass in the total content of 100 parts by mass of components (A) and (B) in the resin composition of the present invention. It is more preferably 30 to 40 parts by mass. Further, when the content of component (A) in the base resin is within the above range, from the viewpoint of suppressing bleeding, the blending amount of the thioether compound of component (C) is suppressed, and the fluororubber of component (D) is mainly used. is preferably used to control the adhesion between the wire coating material and the conductor.
Further, when the cross-sectional area of the insulated wire of the present invention is 3 sq or more, from the viewpoint of imparting flexibility to the insulated wire, the resin composition of the present invention, which is a film-forming material, contains ethylene-acetic acid as the component (B). It is preferable to blend a large amount of the vinyl copolymer. Specifically, the content of component (B) is preferably 80 to 95 parts by mass in the total content of 100 parts by mass of components (A) and (B) in the resin composition of the present invention. It is more preferably 90 to 95 parts by mass.

[Automotive wire harness]
The wiring harness for automobiles of the present invention has the insulated wire of the present invention. The resin composition of the present invention has an excellent appearance, flame retardancy and mechanical properties. Therefore, a wire harness incorporating an insulated wire having a layer made of a resin coating material obtained by cross-linking the resin composition of the present invention can be suitably used for automobiles.
Hereinafter, the wire harness for automobiles may be simply referred to as "wire harness".

[Manufacturing method of insulated wire used for wire harness for automobile]
The insulated wire used in the wiring harness for automobiles of the present invention is provided with a layer of the resin composition by extrusion coating the resin composition of the present invention on the conductor, and the layer of the resin composition is irradiated with an electron beam of 80 to 250 kGy. It can be obtained through a step of irradiation. This electron beam irradiation causes a cross-linking reaction in the resin composition layer to form a resin coating material layer.

The conductor may be solid or stranded, and may be bare, tinned or enamel-coated. Examples of metal materials for forming conductors include annealed copper, copper alloys, and aluminum. The thickness of the resin coating material layer formed around the conductor is not particularly limited, but is usually about 0.15 to 5 mm.
The diameter of the conductor, the material of the conductor, the thickness of the coating layer, etc. are not particularly limited, and can be appropriately determined according to the purpose and application. The cross-linking reaction by electron beam irradiation can be carried out by usual methods and conditions, and is not limited. The electron beam irradiation conditions are preferably an irradiation amount of 50 to 450 kGy, more preferably 80 to 250 kGy, even more preferably 80 to 200 kGy, and particularly preferably 80 to 160 kGy. Also, the acceleration voltage is preferably 300 to 3000 keV, more preferably 500 to 2500 keV.
Also, a multi-layered structure may be employed in which an intermediate layer or shielding layer is provided between the conductor and the covering layer or between the covering layers.

The conditions for extruding the resin composition of the present invention are not particularly limited as long as the resin composition of the present invention can be extruded. The extrusion temperature (head portion) is preferably 100 to 230°C, more preferably 120 to 200°C, in that it can also ensure the
Other conditions for extrusion molding can be appropriately set according to the purpose.
The screw configuration of the extruder is not particularly limited, and a normal full-flight screw, double-flight screw, tip double-flight screw, Maddock screw, or the like can be used.

The shape and material of the conductor may be of any shape and material (copper, aluminum, etc.) generally used for insulated wires used in wire harnesses for automobiles.
Moreover, the thickness of the resin coating layer is not particularly limited. When the resin composition of the present invention is used, there is an advantage that an insulated wire having excellent flexibility, hardness, cross-linking degree, flame retardancy, cold resistance and heat resistance can be obtained even if the thickness of the resin coating layer is reduced. .

The present invention will be described in more detail based on the following examples and comparative examples, but the present invention is not limited to these.

[Examples 1 to 8 and Comparative Examples 1 to 9]
Materials for preparing the resin compositions of Examples 1-8 and Comparative Examples 1-9 are shown in Tables 1 and 2 below. Details of the materials used are as follows. (1) to (18) below correspond to (1) to (18) in Tables 1 and 2 below.

<Materials used>
(Component (A): polyethylene (PE) resin)
(1): NUC-9060 (trade name), manufactured by NUC, density 0.923 g/cm ³
(2): NUCG-5130 (trade name), manufactured by Dow Elastomers, density 0.923 g/cm ³
(3): ENGAGE-8100 (trade name), manufactured by NUC, density 0.870 g/cm ³
(4): HI-ZEX-5305E (trade name), manufactured by Prime Polymer Co., Ltd., density 0.950 g/cm ³
(5): Adtex L6100M (trade name), manufactured by Nippon Polyolefin Co., Ltd., density 0.920 g/cm ³ , modified with maleic acid

(Component (B): vinyl acetate copolymer resin)
(6): Evaflex V5961 (trade name), manufactured by DuPont Mitsui Polychemicals, content of vinyl acetate component: 9% by mass
(7): Evaflex V5274 (trade name), manufactured by DuPont Mitsui Polychemicals, Inc. Content of vinyl acetate component: 17% by mass
(8): Evaflex EV170 (trade name), manufactured by DuPont Mitsui Polychemicals, content of vinyl acetate component: 33% by mass
(9): Evaflex EV40LX (trade name), manufactured by DuPont Mitsui Polychemicals, content of vinyl acetate component: 41% by mass
(10): Evaflex EV45LX (trade name), manufactured by DuPont Mitsui Polychemicals, content of vinyl acetate component: 46% by mass

(Component (C): thioether compound)
(11): 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diyl bis[3-dodecylthiopropionate], Adekastab AO-412S (trade name) , manufactured by ADEKA

(Component (D): fluororubber)
(12): Viton FreeFlow 10 (trade name), manufactured by Chemours

(Flame retardants)
(13): 1,2-bis(pentabromophenyl)ethane, Cytex 8010 (trade name), manufactured by Albemarle (14): Antimony trioxide, PATOX-C (trade name), manufactured by Nippon Seiko Co., Ltd.

(Antioxidant)
(15): Pentaerythrityl-tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), phenolic antioxidant, Irganox 1010 (trade name), manufactured by BASF (16) : Imidazole antioxidant, zinc salt of 2-sulfanylbenzimidazole, Nocrac MBZ (trade name), manufactured by Ouchi Shinko Kagaku Co., Ltd.

(processing aid)
(17): Zinc stearate, Shinaka Red ZS-101 (trade name), manufactured by Shinagawa Kako Co., Ltd.

(crosslinking aid)
(18): Trimethylolpropane trimethacrylate, Ogmont T200 (trade name), manufactured by Shin-Nakamura Chemical Co., Ltd.

<Production of resin composition pellets>
According to the compositions shown in Tables 1 and 2 below, melt-kneaded at 180 ° C. using a 1.7 liter Banbury mixer, discharged the mixture, granulated through an extruder, Examples 1-8 and Comparative Examples 1- No. 9 resin composition pellets were obtained.

<Production of insulated wires>
Each resin composition pellet obtained above was extrusion-coated on a conductor using an extruder set at a temperature of 130 to 190°C. The formed layer of the resin composition was subjected to a cross-linking reaction by electron beam irradiation. In this way, an insulated wire having an insulating film with a thickness of 0.7 mm around the conductor made of copper and having a circular cross-section with a cross-sectional area of 3 mm ² (≈3 sq) was obtained.
The cross-linking by the electron beam was performed under the conditions of 160 kGy at an accelerating voltage of 800 keV.

[Performance evaluation]
Using each insulated wire manufactured as described above, the following performance evaluation was performed.

<Surface smoothness>
The surface smoothness (extrusion appearance) of each insulated wire was measured as follows.
Using a laser microscope (LASER MICROSCOPE VK-X250, manufactured by KEYENCE), the surface of each insulated wire is measured in the longitudinal direction under the conditions of a stylus tip curvature radius of 2 μm and a static measurement force of 0.75 mN at the stylus average position. Measured along each. Each measurement was performed three times (N=3), and the average value was taken as the arithmetic mean roughness Ra (μm). The calculated arithmetic mean roughness Ra was evaluated according to the following criteria. In addition, evaluation A and B were made into the pass.

-Evaluation criteria-
A: Ra is less than 2 μm B: Ra is 2 μm or more and less than 3 μm C: Ra is 3 μm or more

<Extrusion workability>
At the time of extruding 5000 m length onto the conductor under the conditions described above, the resin scum (dice scum, die scum) deposited on the extrusion port and the resin scum adhering to the insulated wire were evaluated according to the following criteria. Evaluations A and B were regarded as acceptable. The insulated wires obtained by extrusion were successively removed with an air gun to remove resin residue. The air gun used (trade name: AG45, manufactured by Kurita Seisakusho) had a tip diameter of φ2.0 and an air pressure of 0.5 MPa.

-Evaluation criteria-
A: At the time of production of 5000 m, resin scum did not deposit or adhere to the extrusion port and the insulated wire.
B: At the time of production of 5000 m, resin residue was deposited on the extrusion port, but no resin residue was observed to adhere to the insulated wire after jetting with an air gun.
C: At the time of production of 5000 m, resin residue was deposited on the extrusion port, and adherence of resin residue to the insulated wire was observed after spraying with an air gun.

<Bleeding>
The insulated wire precursor (before electron beam irradiation) (length: 200 mm) coated with the resin composition by extrusion was kept at 40° C. for 1 hour. A SUS304 round bar (φ20 × 300 mm, hereinafter also referred to as “SUS bar”) was placed perpendicular to the longitudinal direction of the insulated wire precursor so as to be in contact with the surface of the insulated wire precursor (surface of the layer of the resin composition). In the positional relationship of the direction, the insulated wire precursor was reciprocated 10 times in the longitudinal direction (1 reciprocation: 200 mm × 2 times), and the amount of deposits derived from each insulated wire attached to the SUS304 round bar (the surface bleeding component of the insulated wire) adhesion) was evaluated. Adhesion of bleeding components was visually observed, and evaluations A and B were regarded as acceptable.

-Evaluation criteria-
A: There was no adhesion of bleeding components.
B: The adhesion area of the bleed component was less than half the contact area between the insulated wire precursor and the SUS rod.
C: The adhesion area of the bleed component was half or more of the contact area between the insulated wire precursor and the SUS rod.

<Adhesion>
The adhesion between the insulating coating layer and the conductor was measured by a method according to the Japan Society of Automotive Engineers standard JASO D618.
Of the 75 mm insulated wire, the insulation coating layer is removed from the tip to 25 mm to expose the conductor, the pulling speed is 250 mm / min at room temperature (23 ° C), and when the conductor is pulled, the resin coating layer falls off from the conductor. The maximum tensile force up to was measured. The measurement results were evaluated according to the following criteria. In addition, evaluation A and B were made into the pass.

-Evaluation criteria-
A: The maximum tensile force is 10 N or more and less than 40 N B: The maximum tensile force is 40 N or more and less than 80 N C1: The maximum tensile force is less than 10 N C2: The maximum tensile force is 80 N or more

<Flame Retardant>
A tilted burn test was performed according to International Organization for Standardization (ISO) 19642. A wire sample with a length of 600 mm cut from each insulated wire was prepared, and the sample was tilted about 45 degrees with respect to the horizontal and supported. Using a Bunsen burner with a diameter of 10 mm, apply the tip of a 50 mm reducing flame to a point 500 ± 5 mm from the top of the sample for 30 seconds or until the conductor is exposed, and measure the afterflame time after gently removing the flame. was evaluated according to the criteria of In addition, evaluation A and B were made into the pass.

-Evaluation criteria-
A: Afterflame time less than 5 seconds B: Afterflame time 5 seconds or more and less than 30 seconds C: Afterflame time 30 seconds or more

<Tensile properties>
A coating material of an insulated wire was sampled and evaluated according to the following criteria based on Japanese Industrial Standards (JIS) K7161.
A tubular sample was prepared by extracting the conductor from each insulated wire, and the tensile strength (breaking strength, MPa) and breaking elongation (% ) was measured. The term "elongation at break (%)" refers to the percentage increase in the distance between the gauge lines when the sample is broken, relative to the initial distance between the gauge lines. Therefore, an elongation at break of 100% means that the gauge length has doubled. The measured tensile strength and elongation at break were evaluated according to the following evaluation criteria. In addition, evaluation A and B were made into the pass.

-Evaluation criteria-
A: Tensile strength of 20 MPa or more and elongation at break of 400% or more B: Tensile strength of 15 MPa or more and less than 20 MPa and/or elongation at break of 300% or more and less than 400% C: Tensile strength of less than 15 MPa and/or elongation at break of less than 300%

The obtained results are summarized in Tables 1 and 2 below. The amounts described in the table below are parts by mass (mass ratio).

<Notes to the table>
The content of each component in the table is parts by mass. Blanks and "-" mean that the corresponding component is not included.

From Table 2, the insulated wire using the resin composition that did not meet the requirements of the present invention failed at least three evaluation items.
On the other hand, as is clear from Table 1, the insulated wire produced using the resin composition of the present invention passed all the evaluation items. From this, it can be seen that the resin composition of the present invention can be suitably used as a resin coating material layer for an insulated wire.

While we have described our invention in conjunction with embodiments thereof, we do not intend to limit our invention in any detail to the description unless specified otherwise, which is contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted broadly.

Claims

Containing the following components (A) and (B), and containing at least one of the following components (C) and (D),
(A) low density polyethylene resin,
(B) ethylene-vinyl acetate copolymer resin,
(C) a thioether compound,
(D) fluororubber,
The total content of components (A) and (B) is 100 parts by mass, the content of component (A) is 5 to 40 parts by mass, the content of component (B) is 60 to 95 parts by mass, and component (A ) and the total content of components (C) and (D) is 0.05 to 1 part by mass per 100 parts by mass of the total content of (B),
A resin composition in which the proportion of the vinyl acetate component in component (B) is 40% by mass or less.
The resin composition according to claim 1, wherein the proportion of the vinyl acetate component in the component (B) is 7% by mass or more.
The content of the component (C) is 0.7 parts by mass or less and the content of the component (D) is 1 part by mass or less per 100 parts by mass of the total content of the components (A) and (B). , The resin composition according to claim 1 or 2.
In the total content of 100 parts by mass of components (A) and (B), the content of component (A) is more than 20 parts by mass and 40 parts by mass or less, and the content of component (B) is 60 parts by mass or more and 80 parts by mass. Any one of claims 1 to 3, wherein the content of component (C) is 0.5 parts by mass or less relative to the total content of 100 parts by mass of components (A) and (B). The resin composition according to Item.
In the total content of 100 parts by mass of the components (A) and (B), the content of the component (A) is 5 parts by mass or more and 20 parts by mass or less, and the content of the component (B) is 80 parts by mass or more and 95 parts by mass. Part by mass or less, and the total content of the components (C) and (D) is 0.5 to 1 part by mass with respect to the total content of 100 parts by mass of the components (A) and (B). 4. The resin composition according to any one of items 1 to 3.
The VA value calculated by the following formula is 15 or more, and the total content of the components (C) and (D) with respect to the total content of 100 parts by mass of the components (A) and (B) is 0.5 to 1. The resin composition according to any one of claims 1 to 5, which is parts by mass.

VA value = [content (parts by mass) of component (B) in 100 parts by mass of total content of components (A) and (B)] x [proportion of vinyl acetate component in component (B) (% by mass) ]/100
Any one of claims 1 to 6, wherein the resin composition contains, in addition to the components (A) to (D), at least one of a flame retardant, an antioxidant, a processing aid, and a crosslinking aid. The resin composition according to Item.
The resin composition according to any one of claims 1 to 7, which is used for automotive wire harnesses.
A resin coating material obtained by cross-linking the resin composition according to any one of claims 1 to 8.
An insulated wire, the insulating coating of which has the resin coating material according to claim 9.
A wire harness for an automobile, having the insulated wire according to claim 10.
A step of extruding and coating the resin composition according to any one of claims 1 to 8 on a conductor to provide a layer of the resin composition, and irradiating the layer of the resin composition with an electron beam of 80 to 250 kGy. A method for manufacturing an insulated wire used for a wire harness for an automobile, comprising: